Stator of a Waterproof Motor and Method for Manufacturing the same

ABSTRACT

A method for manufacturing a stator of a waterproof motor includes disposing a first assembly in a mold where the first assembly includes a coil unit wound around an iron core assembly, and filling the mold with a thermosetting plastic which forms a housing after curing. The housing houses the coil unit and the iron core assembly. A recess is formed at one end of the housing. The method further includes disposing a second assembly in the recess of the housing where the second assembly includes a circuit unit, and filling the recess of the housing with a waterproof glue which envelopes the circuit unit after curing. According to the above, the stator of the waterproof motor is formed.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.16/217,245 filed on Dec. 12, 2018. The application claims the benefit ofTaiwan application serial No. 107104551, filed on Feb. 8, 2018, and theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to a component of a motor and amethod for manufacturing the component of the motor and, moreparticularly, to a stator of a waterproof motor and a method formanufacturing the stator of the waterproof motor.

2. Description of the Related Art

FIG. 1 shows a stator 9 of a waterproof motor manufactured by aconventional manufacturing method. The conventional manufacturing methodincludes forming a stator assembly 91 in a mold, filling the spacebetween the stator assembly 91 and the cavity wall of the mold with afiller, and removing the mold to obtain the stator 9 of the waterproofmotor. The stator 9 includes a protective layer 92. An embodiment ofsuch a method for manufacturing a stator of a waterproof motor isdisclosed in U.S. Patent Publication No. 2007/0085426 (Taiwan Patent No.1344253).

Although the conventional manufacturing method can form the protectivelayer 92 in a single process, the electronic components of the statorassembly 91 are often damaged by the large injection pressure of thethermosetting material which forms the protective layer 92. As a result,it is difficult to increase the yield rate. In another case where thewaterproof glue is used as the material of the protective layer 92, ittakes dozens of hours to cure the waterproof glue. This requires anextra process of baking the waterproof glue. Disadvantageously, theyield rate is low and the energy consumption is high.

In light of this, it is necessary to improve the conventional method formanufacturing a stator of a waterproof motor.

SUMMARY OF THE INVENTION

It is therefore the objective of this invention to provide a method formanufacturing a stator of a waterproof motor which can lower the damageto the components and reduces the amount of the waterproof glue used.

In an aspect, a method for manufacturing a stator of a waterproof motorincludes disposing a first assembly in a mold where the first assemblyincludes a coil unit wound around an iron core assembly, and filling themold with a thermosetting plastic which forms a housing after curing.The housing houses the coil unit and the iron core assembly. A recess isformed at one end of the housing. The method further includes disposinga second assembly in the recess of the housing where the second assemblyincludes a circuit unit, and filling the recess of the housing with awaterproof glue which envelopes the circuit unit after curing. Accordingto the above, the stator of the waterproof motor is formed.

In an example, the method for manufacturing the stator of the waterproofmotor further includes coupling the iron core assembly with an outerperiphery of a shaft tube of the first assembly before forming thehousing. The housing is coupled with the outer periphery of the shafttube. One end of the shaft tube is not enveloped by the housing andextends into the recess of the housing. Thus, it is ensured that theliquid will not be able to intrude into the gap between the shaft tubeand the housing, improving the waterproof effect of the motor.

In the example, disposing the second assembly includes connecting acircuit connector of the circuit unit to a coil connector of the coilunit which is exposed to the recess of the housing, and filling therecess includes enveloping the coil connector of the coil unit and thecircuit unit with the waterproof glue. Thus, the waterproof effect andthe convenience in assembly are improved.

In the example, the coil unit includes a wire wound around a post of theiron core assembly. A free end of the post extends out of the housingand is exposed to the recess after forming the housing. Disposing thesecond assembly includes disposing a circuit board of the circuit unitin the recess of the housing and engaging the circuit board of thecircuit unit with the post of the iron core assembly, and filling therecess includes enveloping the post and the circuit board with thewaterproof glue. Thus, the waterproof effect and the convenience inassembly are improved.

In another aspect, a method for manufacturing a stator of a waterproofmotor includes disposing a first assembly in a mold where the firstassembly includes a coil unit wound around an iron core assembly,positioning a second assembly in an electric box which includes acircuit unit, and filling the mold with a thermosetting plastic whichforms a housing after curing. The housing houses the coil unit and theiron core assembly. A recess is formed at one end of the housing. Aretaining ring forms at a circumferential edge of the recess. The methodfurther includes filling the electric box with a waterproof glue whichenvelopes the circuit unit after curing, and engaging the electric boxwith the housing to press the retaining ring against the waterproofglue. According to the above, the stator of the waterproof motor isformed.

In an example, engaging the electric box includes connecting a circuitconnector of the circuit unit, which is exposed out of the waterproofglue, to a coil connector of the coil unit which is exposed out of thehousing before pressing the retaining ring against the waterproof glue.Thus, the waterproof effect and the convenience in assembly areimproved.

In the example, the thermosetting plastic is bulk molding compound (BMC)and the waterproof glue is polyurethane (PU) or silicone glue. Thus, thequality of the waterproof motor is improved.

In a further aspect, a stator of a waterproof motor includes a firstassembly having a coil unit wound around an iron core assembly, ahousing made of thermosetting plastic and enveloping the coil unit andthe iron core assembly where a recess is formed at one end of thehousing, and a second assembly disposed in the recess of the housing andincluding a circuit unit. The recess is filled with a waterproof gluewhich envelops the circuit unit.

In an example, the first assembly includes a shaft tube and the ironcore assembly is coupled with an outer periphery of the shaft tube. Thehousing is coupled with the outer periphery of the shaft tube. One endof the shaft tube is not enveloped by the housing and extends into therecess. Thus, it is ensured that the liquid will not be able to intrudeinto the gap between the shaft tube and the housing, improving thewaterproof effect of the motor.

In the example, the coil unit includes a coil connector exposed to therecess of the housing and connected to a circuit connector of thecircuit unit, and the waterproof glue envelopes the coil connector ofthe coil unit and the circuit unit. Thus, the waterproof effect and theconvenience in assembly are improved.

In the example, the second assembly includes a support coupled with theshaft tube and located in the recess of the housing, and the circuitunit includes a circuit board coupled with the support. Thus, thecircuit board can be securely positioned in the recess of the housing.

In the example, a shoulder portion is provided on the outer periphery ofthe shaft tube. The housing includes an axial extension portion abuttingthe outer periphery of the shaft tube and extending into the recess ofthe housing. A free end of the axial extension portion abuts theshoulder portion. The support is connected to the axial extensionportion Thus, the reliability in engagement between the housing and theshaft tube is improved.

In the example, the iron core assembly includes a post having a free endextending out of the housing and exposed to the recess. The coil unitincludes a wire wound around the post of the iron core assembly. Thecircuit unit includes a circuit board located in the recess of thehousing and engaged with the post of the iron core assembly. Thewaterproof glue envelopes the post and the circuit board. Thus, theconvenience in assembly is improved.

In still a further aspect, a stator of a waterproof motor includes afirst assembly having a coil unit wound around an iron core assembly, asecond assembly including a circuit unit, and a housing made ofthermosetting plastic and enveloping the coil unit and the iron coreassembly. A recess is formed at one end of the housing. A retaining ringforms at a circumferential edge of the recess. The stator of thewaterproof motor further includes an electric box receiving the secondassembly and filled with a waterproof glue to envelope the circuit unitwith the waterproof glue. The electric box and the housing are coupledwith each other. The retaining ring is pressed against the waterproofglue.

In an example, the coil unit includes a coil connector exposed out ofthe housing and connected to a circuit connector of the circuit unitwhich is exposed out of the waterproof glue, and the coil connector ofthe coil unit is connected to the circuit connector of the circuit unitin an inner space delimited by an inner periphery of the retaining ring.Thus, the waterproof effect and the convenience in assembly areimproved.

In the example, a rotor space is formed at a center of the housing, andthe housing includes a shaft-coupling portion located in the rotorspace. Thus, the convenience in assembly is improved.

In the example, the housing includes a plurality of screwing portionssurrounding the retaining ring and screwed to a plurality of screwingportions of the electric box. Thus, the waterproof effect is improved.

In the example, the plurality of screwing portions of the housing islocated outside the waterproof glue. Thus, it can prevent the fastenersfrom damaging the waterproof glue.

In the example, a wire groove is provided surrounding an outer peripheryof the retaining ring. The wire groove is not intercommunicating with aninner space delimited by an inner periphery of the retaining ring. Thecircuit unit includes a wire connected to a circuit board. A portion ofthe wire that is connected to the circuit board is enveloped by thewaterproof glue. The wire is partially exposed out of the waterproofglue and extends out of the housing through the wire groove. Thus, thewaterproof glue can prevent the wire from breaking somewhere around thecircuit board and prevent the liquid from permeating into the innerspace of the retaining ring when the wire is being pulled out of thehousing. As a result, the convenience in connecting the wire to anexternal power supply and the waterproof effect are improved.

Based on the above, the stator of the waterproof motor and the methodfor manufacturing the same can significantly reduce the amount of thewaterproof glue used. Thus, the yield rate and quality of the product aswell as the production efficiency are improved while the manufacturingcost is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a cross sectional view of a stator of a conventionalwaterproof motor.

FIG. 2 is a cross sectional view of a first assembly of a stator of awaterproof motor according to a first embodiment of the invention.

FIG. 3 is a cross sectional view of a housing and the first assembly ofFIG. 2.

FIG. 4 is a cross sectional view of a second assembly and the housingand the first assembly of FIG. 3.

FIG. 5 is a cross sectional view of the stator of the first embodimentfilled with a waterproof glue.

FIG. 6 is a cross sectional view of the stator of the first embodimentwhich is coupled with a rotor.

FIG. 7 is a cross sectional view of a stator of a waterproof motoraccording to a second embodiment of the invention.

FIG. 8 is a cross sectional view of a first assembly and an electric boxof a stator of a waterproof motor according to a third embodiment of theinvention.

FIG. 9 is a cross sectional view of the stator of the waterproof motorof the third embodiment where the electric box is filled with awaterproof glue and a housing is formed.

FIG. 10 is a longitudinal cross sectional view of the housing and thefirst assembly of the stator taken along line 10-10 of FIG. 9.

FIG. 11 is a top view of a circuit unit and the electric box of thestator taken along line 11-11 of FIG. 9.

FIG. 12 is an assembled, cross sectional view of the stator of thewaterproof motor according to the third embodiment of the invention.

FIG. 13 is a cross sectional view of the stator of the third embodimentwhich is coupled with a rotor.

In the various figures of the drawings, the same numerals designate thesame or similar parts. Furthermore, when the terms “first”, “second”,“third”, “fourth”, “inner”, “outer”, “top”, “bottom”, “front”, “rear”and similar terms are used hereinafter, it should be understood thatthese terms have reference only to the structure shown in the drawingsas it would appear to a person viewing the drawings, and are utilizedonly to facilitate describing the invention.

DETAILED DESCRIPTION OF THE INVENTION

A method for manufacturing a stator of a waterproof motor according to afirst embodiment of the invention includes the steps described asfollows.

Referring to FIG. 2, the method for manufacturing the stator of thewaterproof motor includes disposing a first assembly 1 in a mold (notshown). The first assembly 1 at least includes a coil unit 11 woundaround an iron core assembly 12. In this embodiment, the iron coreassembly 12 includes a plurality of silicon steel plates 121 and aninsulating sleeve unit 122. The silicon steel plates 121 are stackedtogether and are clamped by the insulating sleeve unit 122. The coilunit 11 is radially wound around the insulating sleeve unit 122.

Referring to FIG. 3, the method for manufacturing the stator of thewaterproof motor further includes filling the mold with a thermosettingplastic. The thermosetting plastic forms a housing 2 which envelopes thecoil unit 11 and the iron core assembly 12 after curing. A recess 21 isformed at one end of the housing 2. The thermosetting plastic may beepoxy resin, Preferably, the thermosetting plastic is thermosettingplastic formed by injecting molding, such as bulk molding compound(BMC). The bulk molding compound is lightweight and has a high strengthand a low shrinkage rate. The bulk molding compound is highlytemperature-resistant and moisture-resistant. The bulk molding compoundpermits the mold removal at an angle of 0 degree. This improves not onlythe formation rate and formation efficiency of the housing 2 but alsothe quality of the produced waterproof motor.

Referring to both FIGS. 2 and 3 again, it is worth mentioning that thefirst assembly 1 in this embodiment preferably includes a shaft tube 13.Before the formation of the housing 2, the iron core assembly 12 can befixed to the outer periphery of the shaft tube 13 to couple the housing2 to the outer periphery of the shaft tube 13 after the housing 2 cures.At the same time, one end of the shaft tube 13 is not enveloped by thehousing 2 and protrudes into the recess 21. In this arrangement, thewatertight effect between the shaft tube 13 and the housing 2 isimproved, ensuring that the liquid will not be able to intrude into thegap between the shaft tube 13 and the housing 2. Furthermore, a shoulderportion 131 may be provided on the outer periphery of the shaft tube 13.Thus, during the formation of the housing 2, the housing 2 can form anaxial extension portion 22 abutting the outer periphery of the shafttube 13 and extending into the recess 21. A free end of the axialextension portion 22 abuts the shoulder portion 131 of the shaft tube13. As a result, the convenience in positioning the shaft tube 13 in themold is improved, thereby forming the housing 2. In addition, thearrangement of the axial extension portion 22 increases the contact areabetween the housing 2 and the shaft tube 13, thus providing a morereliable engagement effect between the housing 2 and the shaft tube 13.

Referring to FIG. 4, the method further includes positioning a secondassembly 3 in the recess 21 of the housing 2. The second assembly 3includes at least a circuit unit 31, The circuit unit 31 may include acircuit board 311 and a plurality of electronic components 312 mountedon the circuit board 311. In this embodiment, the second assembly 3 mayfurther include a support 32. After the formation of the housing 2, thesupport 32 can be coupled with the axial extension portion 22 of thehousing 2, such that the support 32 is fixed to the outer periphery ofthe shaft tube 13 and is located in the recess 21 of the housing 2.Then, the circuit board 311 of the circuit unit 31 is coupled with thesupport 32 such that the circuit board 311 can be stably positioned inthe recess 21. In another embodiment, the support 32 can be formed atthe time the housing 2 is formed. In other words, the support 32 and thehousing 2 are integrally formed with each other.

Referring to FIG. 5, the method further includes filling the recess 21with a waterproof glue 4 to envelope the circuit unit 31, thus obtainingthe stator of the waterproof motor of the first embodiment of theinvention. The waterproof glue 4 may be polyurethane (PU) or siliconeglue.

Referring to FIGS. 4 and 5 again, the coil unit 11 of the first assembly1 may include a coil connector 111. During the formation of the housing2, the housing 2 may not envelope the coil connector 111 such that thecoil connector 111 is exposed to the recess 21. In this regard, thecircuit unit 31 includes a circuit connector 313 connected to thecircuit board 311. Therefore, when the second assembly 3 is positionedin the recess 21 the coil connector 111 of the coil unit 11 can beconnected to the circuit connector 313 of the circuit unit 31. Then, therecess 21 is filled with the waterproof glue 4 to envelope the coilconnector 111 of the coil unit 11 and the entire circuit unit 31, Inanother embodiment, the wire of the coil unit 11 can be directly weldedto the circuit board 311 to electrically connect the coil unit 11 to thecircuit board 311.

Referring to FIG. 5, based on the above process, the method formanufacturing the stator of the waterproof motor according to the firstembodiment of the invention can achieve at least the advantages ofimproved yield rate, improved quality, improved production efficiencyand higher production capacity, and reduced manufacturing cost.

With respect to the first advantage (improved yield rate), themanufacturing method of the invention envelopes the fragile parts of themotor with the waterproof glue 4 that has a relatively smaller fillingpressure, and envelopes the strong parts of the motor with athermosetting plastic that has a relatively larger injection pressure.In this manner, there are hardly components damaged during the formationof the waterproof structure, significantly improving the yield rate ofthe product.

With respect to the second advantage (improved quality), under the highyield rate stated above, the manufacturing method of the inventionpermits the thermosetting plastic to fill the tiny gaps inside the moldbased on the high flowability of the thermosetting plastic. Thus, thethermosetting plastic can completely envelope those parts of the firstassembly 1 which requires sealing, thereby providing the first assembly1 with excellent insulating function and waterproof function. As aresult, higher yield rate and product quality are attained.

With respect to the third advantage (improved production efficiency andhigher production capacity), the majority part of the stator of thewaterproof motor can be enveloped by the thermosetting plastic while theminority part of the stator which is more easily broken is enveloped bythe waterproof glue 4. Thus, the amount of the waterproof glue 4 asrequired is significantly reduced. Following the injection molding, thebulk molding compound (BMC) can cure almost as soon as the mold isremoved, thereby reducing the amount of the waterproof glue 4 used andsignificantly shortening the time it takes for the waterproof glue 4 tocure, Advantageously, the method for manufacturing the stator of thewaterproof motor according to the invention can significantly improvethe production efficiency and the production capacity.

With respect to the fourth advantage (reduced manufacturing cost), themethod for manufacturing the stator of the waterproof motor according tothe invention can significantly reduce the amount of the waterproof glue4 used and reduce the energy required to bake the waterproof glue 4. Asa result, the manufacturing cost is lowered. It is noted that the methodaccording to the invention no longer requires a fixture that is neededfor filling purpose of the waterproof glue 4 as the recess 21 is formedduring the formation of the housing 2 for filling purpose of thewaterproof glue 4. Thus, the expenses resulting from bulk purchase,maintenance and warehousing of the fixtures are not incurred.

Referring to FIG. 5, the stator of the waterproof motor according to thefirst embodiment of the invention can be obtained based on the abovemanufacturing method. The stator includes a first assembly 1, a housing2, a second assembly 3 and a waterproof glue 4. The first assembly 1 atleast includes a coil unit 11 wound around the iron core assembly 12.The housing 2 envelops the coil unit 11 and the iron core assembly 12. Arecess 21 is formed at one end of the housing 2. The second assembly 3is positioned in the recess 21. The second assembly 3 includes at leasta circuit unit 31. The waterproof glue 4 fills the recess 21 andenvelops the circuit unit 31.

The first assembly 1 preferably further includes a shaft tube 13. Theiron core assembly 12 is fixed to the outer periphery of the shaft tube13. The housing 2 is coupled with the outer periphery of the shaft tube13. One end of the shaft tube 13 is not enveloped by the housing 2 andextends into the recess 21. In this embodiment, the second assembly 3includes a support 32 fit around the shaft tube 13 and located in therecess 21 of the housing 2. The circuit unit 31 includes a circuit board311 coupled with the support 32 such that the circuit board 311 can bestably positioned in the recess 21. A shoulder portion 131 is providedon the outer periphery of the shaft tube 13. The housing 2 includes anaxial extension portion 22 abutting the outer periphery of the shafttube 13 and extending into the recess 21 of the housing 2. A free end ofthe axial extension portion 22 abuts the shoulder portion 131. Thesupport 32 is integrally formed with or connected to the axial extensionportion 22. The coil unit 11 includes a coil connector 111 exposed tothe recess 21 of the housing 2 and connected to a circuit connector 313of the circuit unit 31. The waterproof glue 4 envelops the coilconnector 111 of the coil unit 11 and the circuit unit 31.

Referring to FIG. 6, a rotor 8 includes a shaft 81 rotatably coupledwith the shaft tube 13 of the stator of the waterproof motor accordingto the first embodiment of the invention. In this regard, a magnet 82faces the iron core assembly 12. After the stator is electrified togenerate a magnetic field, the rotor 8 is driven to rotate. Besides, aseat B includes a retaining ring R. The seat B is coupled with the shafttube 13 while the retaining ring R is pressed against the waterproofglue 4.

FIG. 7 shows a stator of a waterproof motor as manufactured by amanufacturing method according to a second embodiment of the invention.The stator of the waterproof motor in FIG. 7 is substantially the sameas that of the first embodiment except for the manner the secondassembly 3 is positioned in the recess 21 of the housing 2.

Specifically, the iron core assembly 12 of the first assembly 1 in thisembodiment includes a post 123. The post 123 is an electricallyconductive post on the insulating sleeve unit 122. A wire 112 of thecoil unit 11 is wound around the coil unit 11. After the housing 2 isshaped, the portion of the post 123 that is wound with the wire 112 ispreferably enveloped by the housing 2 while the free end of the post 123extends out of the housing 2 and is exposed to the recess 21. After thesecond assembly 3 is disposed in the recess 21, the post 123 extendsthrough and couples with the circuit board 311 of the circuit unit 31 tosimplify the assembly of the second assembly 3. Then, the recess 21 isfilled with the waterproof glue 4 to envelop the post 123 and thecircuit unit 31 in the waterproof glue 4. In this manner, the stator ofthe waterproof motor according to the second embodiment of the inventioncan be obtained and can possess the same advantages as the manufacturingmethod of the first embodiment of the invention.

A method for manufacturing a stator of a waterproof motor according to athird embodiment of the invention includes the steps described asfollows.

Referring to FIG. 8, the method for manufacturing the stator of thewaterproof motor includes disposing a first assembly 1 in a mold (notshown). The first assembly 1 at least includes a coil unit 11 woundaround an iron core assembly 12. In this embodiment, the iron coreassembly 12 includes a plurality of silicon steel plates 121 and aninsulating sleeve unit 122 (including two insulating sleeves). Thesilicon steel plates 121 are stacked together and are clamped by theinsulating sleeve unit 122. The coil unit 11 is radially wound aroundthe insulating sleeve unit 122.

Besides, the second assembly 3 is positioned in an electric box 5. Theelectric box 5 includes at least a circuit unit 31 having a circuitboard 311 and a plurality of electronic components 312 mounted on thecircuit board 311.

Referring to FIG. 9, the mold is filled with the thermosetting plasticwhich forms a housing 6 after curing. The coil unit 11 and the iron coreassembly 12 are enveloped by the housing 6. A recess 61 is formed at oneend of the housing 6. A retaining ring 62 forms near a circumferentialedge of the recess 61. The thermosetting plastic may be epoxy, orpreferably be thermosetting plastic formed by injection molding such asbulk molding compound (BMC).

The electric box 5 is filled with the waterproof glue 7 to envelop thecircuit unit 31 in the waterproof glue 7 (in a manner where at least theelectrically conductive parts of the circuit unit 31 are enveloped bythe waterproof glue 7). The waterproof glue 7 may be polyurethane (PU)or silicone glue.

Referring to FIG. 12, the electric box 5 and the housing 6 are coupledwith each other such that the retaining ring 62 is pressed against thewaterproof glue 7. Accordingly, the stator of the waterproof motoraccording to the third embodiment of the invention is obtained. When theretaining ring 62 is pressed against the waterproof glue 7, thewaterproof glue 7 can deform under the force to close up the opening ofthe retaining ring 62. This ensures that the liquid will not intrudeinto the inner space delimited by the inner periphery of the retainingring 62.

Referring to FIGS. 9 and 12 again, it is noted that the coil unit 11 ofthe first assembly 1 includes a coil connector 111, which is exposed outof the housing 6 after the formation of the housing 6. The circuit unit31 includes a circuit connector 313 exposed out of the waterproof glue7. In this arrangement, during the assembly of the electric box 5 andthe housing 6, the circuit connector 313 of the circuit unit 31 can beconnected to the coil connector 111 of the coil unit 11 and then theretaining ring 62 is pressed against the waterproof glue 7.

Based on the above steps, the method for manufacturing the stator of thewaterproof motor according to the third embodiment of the invention canachieve the same advantage as the first embodiment. It is noted that thewaterproof glue 7 is filled into the electric box 5 such that it willnot incur the costs of purchase, maintenance and warehousing of thefixtures required for filling purposes of the waterproof glue 7,Moreover, the retaining ring 62 can be formed during the formation ofthe housing 6, thus omitting the use of a washer (such as an O-ring)during the assembly of the electric box 5 and the housing 6. In thisarrangement, it can be ensured that the liquid will not intrude into theinner space of the waterproof motor, simplifying the structure andimproving the efficiency in assembly of the waterproof motor.

Referring to FIG. 12, based on the manufacturing method according to thethird embodiment of the invention, the stator of the waterproof motor ofthe third embodiment can be obtained. The stator includes a firstassembly 1, a second assembly 3, a housing 6, an electric box 5 and awaterproof glue 7. The first assembly 1 at least includes a coil unit 11wound around an iron core assembly 12. The second assembly 3 includes atleast a circuit unit 31, The housing 6 is made of thermosetting plasticand envelops the coil unit 11 and the iron core assembly 12. A recess 61is formed at one end of the housing 6. A retaining ring 62 forms at acircumferential edge of the recess 61. The second assembly 3 is disposedin the electric box 5. The waterproof glue 7 fills the inner space ofthe electric box 5 to envelope the circuit unit 31 (in a manner where atleast the electrically conductive parts of the circuit unit 31 areenveloped by the waterproof glue 7). The electric box 5 is coupled withthe housing 6 while the retaining ring 62 of the housing 6 is pressedagainst the waterproof glue 7.

The coil unit 11 includes a coil connector 111 exposed out of thehousing 6. The circuit unit 31 includes a circuit connector 313 exposedout of the waterproof glue 7. The coil connector 111 of the coil unit 11is connected to the circuit connector 313 of the circuit unit 31 in theinner space delimited by the inner periphery of the retaining ring 62. Arotor space 63 is formed at the center of the housing 6. The housing 6further includes a shaft-coupling portion 64 located in the rotor space63, Accordingly, referring to FIG. 13, a rotor 8′ can be rotatablycoupled with the shaft-coupling portion 64 via a shaft 81′. Therefore, amagnet 82′ which surrounds the shaft 81′ can be located in the rotorspace 63 and is radially aligned with the iron core assembly 12. In thisarrangement, the stator of the waterproof motor is electrified togenerate a magnetic field, driving the rotor 8′ to rotate.

Specifically, referring to FIGS. 10 and 12, the electric box 5 includesa plurality of screwing portions 51 and the housing 6 also includes aplurality of screwing portions 65. A fastener S can be screwed through acorresponding pair of the screwing portions 51 and 65. As the liquidwill inevitably intrude into the inner space of the motor through thescrewing portions 51 and 65, the plurality of screwing portions 65preferably surrounds the retaining ring 62. In this arrangement,although the liquid can permeate into the plurality of screwing portions51 and the plurality of screwing portions 65, the liquid cannot permeatefurther into the inner space delimited by the inner periphery of theretaining ring 62 as the retaining ring 62 is pressed against thewaterproof glue 7. Thus, the waterproof effect of the stator of themotor is improved.

A wire groove 621 is provided surrounding the outer periphery of theretaining ring 62. The wire groove 621 is not intercommunicating withthe inner periphery of the retaining ring 62. The circuit unit 31includes a wire 314 connected to the circuit board 311. The portion ofthe wire 314 that is connected to the circuit board 311 is enveloped bythe waterproof glue 7. The wire 314 is partially exposed out of thewaterproof glue 7 and extends out of the housing 6 through the wiregroove 621, so as to connect to an external power supply. In thisarrangement, the waterproof glue 7 can prevent the wire 314 frombreaking somewhere around the circuit board 311 and prevent the liquidfrom permeating into the inner space of the retaining ring 62 when thewire 314 is being pulled out of the housing 6.

Referring to FIGS. 11 and 12, the plurality of screwing portions 51 ofthe electric box 5 may be outside of the range of the waterproof glue 7,preventing the fastener S from breaking the waterproof glue 7 whichadversely affects the waterproof effect of the stator of the motor.

In summary, the stator of the waterproof motor and the method formanufacturing the same can reduce the damage to the electroniccomponents and significantly lowers the amount of the waterproof glueused. Thus, the yield rate and quality of the product as well as theproduction efficiency are improved while the manufacturing cost isreduced.

Although the invention has been described in detail with reference toits presently preferable embodiments, it will be understood by one ofordinary skill in the art that various modifications can be made withoutdeparting from the spirit and the scope of the invention, as set forthin the appended claims.

What is claimed is:
 1. A method for manufacturing a stator of awaterproof motor, comprising: disposing a first assembly in a mold,wherein the first assembly includes a coil unit wound around an ironcore assembly; positioning a second assembly in an electric box, whereinthe second assembly includes a circuit unit; filling the mold with athermosetting plastic which forms a housing after curing, wherein thehousing envelops the coil unit and the iron core assembly, wherein arecess is formed at one end of the housing, and wherein a retaining ringforms at a circumferential edge of the recess; filling the electric boxwith a waterproof glue which envelops the circuit unit after curing; andengaging the electric box with the housing to press the retaining ringagainst the waterproof glue, forming the stator of the waterproof motor.2. The method for manufacturing the stator of the waterproof motor asclaimed in claim 1, wherein engaging the electric box comprisesconnecting a circuit connector of the circuit unit, which is exposed outof the waterproof glue, to a coil connector of the coil unit which isexposed out of the housing before pressing the retaining ring againstthe waterproof glue.
 3. The method for manufacturing the stator of thewaterproof motor as claimed in claim 1, wherein the thermosettingplastic is bulk molding compound (BMC).
 4. The method for manufacturingthe stator of the waterproof motor as claimed in claim 1, wherein thewaterproof glue is polyurethane (PU) or silicone glue.
 5. A stator of awaterproof motor, comprising: a first assembly having a coil unit woundaround an iron core assembly; a second assembly including a circuitunit; a housing made of thermosetting plastic and enveloping the coilunit and the iron core assembly, wherein a recess is formed at one endof the housing, and wherein a retaining ring forms at a circumferentialedge of the recess; and an electric box receiving the second assemblyand filled with a waterproof glue to envelope the circuit unit with thewaterproof glue, wherein the electric box and the housing are coupledwith each other, and wherein the retaining ring is pressed against thewaterproof glue.
 6. The stator of the waterproof motor as claimed inclaim 5, wherein the coil unit includes a coil connector exposed out ofthe housing and connected to a circuit connector of the circuit unitwhich is exposed out of the waterproof glue, and wherein the coilconnector of the coil unit is connected to the circuit connector of thecircuit unit in an inner space delimited by an inner periphery of theretaining ring.
 7. The stator of the waterproof motor as claimed inclaim 5, wherein a rotor space is formed at a center of the housing, andwherein the housing includes a shaft-coupling portion located in therotor space.
 8. The stator of the waterproof motor as claimed in claim5, wherein the housing includes a plurality of screwing portionssurrounding the retaining ring and screwed to a plurality of screwingportions of the electric box.
 9. The stator of the waterproof motor asclaimed in claim 5, wherein the plurality of screwing portions of thehousing is located outside the waterproof glue.
 10. The stator of thewaterproof motor as claimed in claim 5, wherein a wire groove isprovided surrounding an outer periphery of the retaining ring, whereinthe wire groove is not intercommunicating with an inner space delimitedby an inner periphery of the retaining ring, wherein the circuit unitincludes a wire connected to a circuit board, wherein a portion of thewire that is connected to the circuit board is enveloped by thewaterproof glue, and wherein the wire is partially exposed out of thewaterproof glue and extends out of the housing through the wire groove.